With the increase in bit size of digital files processed by electronic apparatus such as a computer system or digital camera, storage problems raised. Small-capacity storage media like floppy discs have been not practical enough to store digital files likely of several million bytes. Hence, flash memory modules with compact size and large capacity up to a couple of gigabytes (GB) are taking the place of conventional storage media. For example, the high-capacity flash memory modules are widely used in computer systems and portable digital peripheral equipments such as digital cameras.
Nowadays, there have been many kinds of memory cards in use, e.g. compact flash (CF) card, memory stick (MS) card, smart media card (SMC), secure digital (SD) card, multimedia card (MMC), microdrive card, etc. Different kinds of memory cards are compliant with different access protocols established by different manufacturers. The interface specification, control chip, and package mechanism of different memory cards are unique and incompatible mutually. Thus various memory cards are required for different electronic apparatus or different uses. Furthermore, the data accessible by an electronic apparatus compliant with a first access protocol is possibly unable to be transferred to another electronic apparatus compliant with a second access protocol. For example, a digital camera designed for a compact flash card cannot communicate with a secure digital card, and a card reader supporting a secure digital card cannot access the data stored in a compact flash card. Therefore, 6-in-1, 7-in-1, or 8-in-1 card readers are developed to cover as many uses as possible. Some slots in the multi-card reader, however, are never used. Hence, it seems to be an inefficient and uneconomic solution.
Please refer to FIG. 1, which is a functional block diagram illustrating a conventional memory card. The memory card 1 mainly includes a flash memory 10 and a controller 11 enclosed with a housing 12. Generally, the basic configuration of the flash memory 10 of the memory card 1 is identical to any other kinds of memory card currently used. But the controller 11 is different from that adapted to different access protocol. The dimension and size of the housing 12 also varies according to the memory card specification. Hence, production lines would be complicated for producing various controllers. Further, the stocks of parts for various controllers may cause a problem in cost control.